System and method for producing a multi-layered board having a medium with improved structure

ABSTRACT

A system and method for producing a board product made from paper products that have embossed medium that features an improved structural profile. The improved structural profile may include a triangular flute pattern wherein each flute may exhibit a first linear leg support and a second linear leg support that each support a center apex structure. The apex may have a substantially flat portion that is configured to engage a facing. As such, the board product may further include one or more facings that are adhesively coupled to the embossed medium. Further, the apex of each “triangle” may also have a groove or channel for receiving an adhesive in a continuous and uniform manner.

CROSS-RELATED APPLICATIONS

This application is a divisional filing of U.S. patent application Ser.No. 15/134,106, entitled SYSTEM AND METHOD FOR PRODUCING A MULTI-LAYEREDBOARD HAVING A MEDIUM WITH IMPROVED STRUCTURE, filed 20 Apr. 2016, andis related to U.S. patent application Ser. No. 15/077,250, entitledSYSTEM AND METHOD FOR INDUCING FLUTING IN A PAPER PRODUCT BY EMBOSSINGWITH RESPECT TO MACHINE DIRECTION, filed 22 Mar. 2016, and is related toU.S. patent application Ser. No. 15/088,999, entitled SYSTEM AND METHODFOR PRODUCING MULTI-LAYERED BOARD HAVING A CORRUGATED MEDIUM AND ANEMBOSSED MEDIUM, filed 1 Apr. 2016, further, the present application isalso related to U.S. patent application Ser. No. 15/134,153, entitledSYSTEM AND METHOD FOR PRODUCING A FACING FOR A BOARD PRODUCT WITHSTRATEGICALLY PLACED SCORES filed 20 Apr. 2016; and is related to U.S.patent application Ser. No. 15/134,176 entitled SYSTEM AND METHOD FORPRODUCING AN ARTICULATING BOARD PRODUCT HAVING A FACING WITH SCORE LINESIN REGISTER TO FLUTING filed 20 Apr. 2016; and is related to U.S. patentapplication Ser. No. 15/134,206, entitled SYSTEM AND METHOD FORPRODUCING MULTI-LAYERED BOARD HAVING AT LEAST THREE MEDIUMS WITH ATLEAST TWO MEDIUMS BEING DIFFERENT filed 20 Apr. 2016, all of theforegoing applications are incorporated herein by reference in theirentireties.

BACKGROUND

Modern paper-making techniques use paper machines at paper mills toproduce rolls of paper that, in turn, can be used by board makers toproduce board products (i.e., corrugated board). As a result, rolls ofpaper may be produced from machines that operate continuously. Modernpaper machines typically produce paper from a number of substancesincluding wood pulp that comprise wood fibers (although other fibers mayalso be used). These fibers tend to be elongated and suitable to bealigned next to one another. The fiber starts as a slurry that can befed onto a moving screen from a head box of the paper machine. In modernpaper machines, the fibers tend to align with each other and align witha direction in which the screen is moving. This alignment direction ofunderlying fibers is called the major direction of the paper and is inline with the machine direction. Thus, the major direction is oftensimply called the machine direction (MD) and the paper that is producedhas an associated MD value.

When paper is used to make a board product, portions or layers of theboard product may be corrugated. Conventional corrugating machines willcorrugate the underlying paper product in the cross direction (CD) ofthe paper thereby failing to take advantage of the natural strength biasof the paper in the machine direction. Further, the greater naturalstrength qualities of paper in the machine direction are leftunharnessed by cross corrugation techniques in board making solutions.Further yet, conventional corrugated medium includes flutes that take ona sinusoidal shape because of the shape of the protrusions in aconventional pair of corrugating rolls. As a result, companies thatproduce conventional board products remain entrenched in old productionprocesses that limit the strength of the board product.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects and many of the attendant advantages of the claims will becomemore readily appreciated as the same become better understood byreference to the following detailed description, when taken inconjunction with the accompanying drawings, wherein:

FIG. 1 is an isometric cutaway view of an embossed medium that may bepart of one or more board products according to one or more embodimentsof the subject matter disclosed herein.

FIG. 2 is an isometric cutaway view of an embossed medium having anadhesive applied to tips of medium support structure that may be part ofone or more board products according to one or more embodiments of thesubject matter disclosed herein.

FIGS. 3A-C are profile views of various flute profiles of medium havingimproved structure according to embodiments of the subject matterdisclosed herein.

FIG. 4 is an isometric cutaway views of a board product having theembossed medium of FIG. 1 according to an embodiment of the subjectmatter disclosed herein.

FIG. 5 is a diagram of aspects of a machine configured to produce theboard product of FIG. 4 according to an embodiment of the subject matterdisclosed herein.

DETAILED DESCRIPTION

The following discussion is presented to enable a person skilled in theart to make and use the subject matter disclosed herein. The generalprinciples described herein may be applied to embodiments andapplications other than those detailed above without departing from thespirit and scope of the present detailed description. The presentdisclosure is not intended to be limited to the embodiments shown, butis to be accorded the widest scope consistent with the principles andfeatures disclosed or suggested herein.

By way of overview, the subject matter disclosed herein may be directedto a system and method for producing a board product made from paperproducts that have embossed medium (sometimes called embossed fluting)that features an improved structural profile. The improved structuralprofile may include a triangular flute pattern wherein each flute mayexhibit a first linear leg support and a second linear leg support thateach support a center apex structure. The apex may have a substantiallyflat portion that is configured to engage a facing. As such, the boardproduct may further include one or more facings (sometimes called linersor walls) that are adhesively coupled to the embossed medium. Further,the apex of each “triangle” may also have a groove or channel forreceiving an adhesive in a continuous and uniform manner.

When a board product is produced such that an embossed medium includes aflute profile with linear leg structures flanked by substantially flatapexes, the resulting board strength and overall structure is improvedwith respect to conventionally produced board having corrugated medium.Further, the embossed medium may be produced using a linear embossingprocess that takes advantage of the natural strength of the machinedirection of the paper product. Additional permutations of theunderlying concept of having a cross-corrugated medium and a linearlyembossed medium in the same board product are possible, includingdisposing a facing between the corrugated medium and the embossed mediumand having facings on one or both outer walls of the board product.These advantages and additional aspects of various embodiments of thesubject matter disclosed herein are discussed below with respect toFIGS. 1-5.

Prior to discussing the various embodiments, a brief discussion aboutcross corrugating and linear embossing is presented. As has been brieflystated above, conventional board products include a conventionallyproduced corrugated medium (sometimes called a corrugated fluting),e.g., a cross-corrugated medium. A cross-corrugated medium has flutesformed perpendicular to most underlying fibers of the paper product.This results in flutes that are not aligned with the majority ofunderlying fibers and, therefore, do not take advantage of the naturalstrength of the MD value of the paper (when compared to the CD value).Such a failure to harness the MD value of the paper leads to loss ofopportunity in the manufacturing of board products when specific boardstrength is to be realized. That is, it will necessarily take more paper(heavier paper, larger flutes, and the like) to realize the requiredboard strength.

A linearly-embossed medium is different from a cross-corrugated mediumin that the induced flutes are aligned with the MD value of the paperproduct. This results in flutes that are aligned with the majority ofunderlying fibers and, therefore, take advantage of the natural strengthof the MD value of the paper (when compared to the CD value), Harnessingthe MD value of the paper leads to efficiencies in the manufacturing ofboard products when specific board strength is to be realized. That is,it will necessarily take less paper (lighter paper, smaller flutes, andthe like) to realize the required board strength. Aspects of making,producing, and using linearly embossed mediums are discussed in greaterdetail in U.S. patent application Ser. No. 15/077,250 entitled “SYSTEMAND METHOD FOR INDUCING FLUTING IN A PAPER PRODUCT BY EMBOSSING WITHRESPECT TO MACHINE DIRECTION” and filed on Mar. 22, 2016, which isincorporated herein by reference in its entirety and for all purposes.Thus, the aspects of linearly-embossed mediums will not be discussedfurther for brevity as the discussion now turns to FIGS. 1-5.

FIG. 1 is an isometric cutaway view of an embossed medium 130 that maybe part of one or more board products according to one or moreembodiments of the subject matter disclosed herein. This diagram showsan isometric view of a portion of an embossed medium 130 that may beformed from an embossing process. That is, flutes 131 are formed frompassing the initial paper product through embossing rolls to form flutesusing a linear-embossing technique such that the flutes 131 are formedcongruent with a majority of underlying fibers 125 of the paper. Theflutes 131 are also formed congruent with the machine direction 122. Alinearly-embossed medium 130 harnesses the natural strength of the paperin the machine direction 122 as the flutes 131 are formed in the machinedirection 122 of the paper (e.g., congruent with a majority theunderlying fibers 125). Therefore, a linearly-embossed medium 130 doesharness the natural strength of the paper in the machine direction 122.Such an embossed medium 130 may be a component/layer of a board productas discussed below with respect to FIG. 4.

Further, as is shown in FIG. 1, the flutes 131 may form a triangularpattern when viewed from a cutaway perspective. This flute patternhaving a triangular repeating shape is referred to as a flute profilehereinafter. In the embodiments discussed in the remaining figures, theflute profile provides an improvement in structural integrity of theembossed medium when compared to a flute profile the exhibits acurvilinear or sinusoidal flute profile. Such a curvilinear orsinusoidal flute profile is prevalent in conventional cross-corrugatedmediums. Therefore, the triangular flute profile as shown in FIG. 1 isalso superior to corrugated mediums with respect to medium strength andstructural integrity. Various reasons why this flute profile and othersimilar flute profile exhibit superior strength and structural integrityare presented below with respect to FIGS. 2-3.

FIG. 2 is an isometric cutaway view of an embossed medium 130 having anadhesive 201 applied to the apex structure of the medium supportstructure that may be part of one or more board products according toone or more embodiments of the subject matter disclosed herein. In FIG.2, a closer look at the embossed medium shows a series of flutes thatform an isosceles triangle flute profile. The flute profile may comprisea series of support structures that each include three portions. In thisexample, the three portions are a first leg support structure 211, asecond leg support structure 212, and an apex structure 210. As shown,the apex structure 210 is disposed between the first and second legsupport structures 211 and 212. In this example support structure then,each support structure may have an apex facing up (although up is anarbitrary direction simply shown by virtue of the illustration).

By the same token, a second series of support structures may also eachinclude three portions, but from the downward facing perspective. Inthis respect, the leg support structure 212 also forms a leg supportstructure for a triangle facing downward. Thus, the three portions are afirst leg support structure 214, a second leg support structure 212, andan apex structure 213 disposed between the first and second leg supportstructures 214 and 212. Note that the second leg structure 212 is thesame second leg support structure with respect to the upward facing apex210 and the downward facing apex 213. The flute profile can then bethought of as series of alternating upward 210 and downward 213 facingapexes with alternating linear leg support structures (e.g., 211, 212,and 214) disposed there between.

Each apex 210 and 213 may be formed to be substantially flat so as toprovide a uniform surface to receive the adhesive 201 from a machine forlocating an apex and applying a continuous line of adhesive to eachapex. Then, the embossed medium 130 may be affixed to a facing 140 atthe apexes that have adhesive 201 at the ready. In other embodiments,each apex 210 and 213 may have a groove for facilitating the receivingof the adhesive. With a groove, the adhesive will tend to remain inplace while the embossed medium 130 is moving through a board-makingmachine. Such a grooved apex embodiment is discussed below with respectto FIG. 3C.

The embodiments as discussed with respect to FIGS. 1-2 have an embossedmedium 130 that exhibits an isosceles triangular flute profile havingsuperior strength and improved support structure. One reason that thisembodiment provides superior strength is that the leg support structures211, 212, and 214 are linear. That is, the leg support structures arenot curved and therefore tend to remain fixed and rigid when variousforces are applied from various directions. In a sinusoidal corrugatedmedium, the “legs” are more like a continuous curve of a sinusoidalpattern. Thus, the “apex” of each flute may be the top side of thesinusoidal curve that exhibits a curved, smooth transition to anyportion of the medium that eventually forms a quasi-flat apex. Becauseof the curved, smooth transition on either side of the apex ofconventional corrugated medium, the apex may translate forward andbackward in an undesired manner. With linear leg support structures 211,212, and 214, a more defined structure is provided that resistsunpredictable movement and failure points.

Further, as the well-known maxim goes, the shortest distance between twopoints is a straight line. As applied here, the shortest distancebetween each top-side facing apex and each bottom side facing apex is alinear leg support structure. Thus, having a triangular flute profilenecessarily uses less overall paper to produce the embossed medium (ascompared to a sinusoidal corrugated medium). Other embodiments mayinclude different shapes for a flute profile including saw-tooth,trapezoidal, or any manner of a geometric shape that exhibits linear legsupport structures flanked by alternating top-side and bottom-sideapexes. Three such embodiments are shown in FIGS. 3A-C and discussednext.

FIGS. 3A-C are profile views of various flute profiles of medium havingimproved structure according to embodiments of the subject matterdisclosed herein. In FIG. 3A, a first isosceles triangle flute profile300 is shown. This flute profile 300 is also shown in FIGS. 1 and 2, butthis view provides a cross-section view of the actual flute profile. Inthis embodiment, each flute includes a first linear leg supportstructure 301 and a second linear leg support structure 302 that areeach coupled to one apex 303 disposed there between. The apex 303 isdisposed substantially flat and in a plane that is parallel to aneventual facing that may be coupled (via adhesive, or other means notshown). Further, the width of the apex 303 in this embodiment isapproximately one tenth of the length of each linear leg supportstructure 301 and 302. Thus, this embodiment may be referred to as anarrow apex flute profile 300.

In this embodiment, the angle of each leg 301 and 302 with respect toeach apex 303 may be approximately 60 degrees. However, any number ofleg angles may be realized. Thus, the first linear leg structure 301 andthe second linear leg structure 302 may be affixed with respect to theapex 303 plane at an angle between approximately 30 degrees and 60degrees.

In FIG. 3B, a second isosceles triangle flute profile 320 is shown. Thisflute profile 320 view provides a cross-section view of the actual fluteprofile exhibiting a first linear leg support structure 321 and a secondlinear leg support structure 322 that are each coupled to one apex 323disposed there between. Further, the apex 323 is disposed substantiallyflat and in a plane that is parallel to an eventual facing that may becoupled. Different from FIG. 3A, the width of the apex 323 in thisembodiment is approximately one fifth of the length of each linear legsupport structure 321 and 322. Thus, this embodiment may be referred toas a wide apex flute profile 320.

In FIG. 3C, a third isosceles triangle flute profile 340 is shown. Thisflute profile 340 view provides a cross-section view a flute profileexhibiting a first linear leg support structure 341 and a second linearleg support structure 342 that are each coupled to one apex 343 disposedthere between. As before, the apex 343 is disposed substantially flatand in a plane that is parallel to an eventual facing that may becoupled. Different from FIGS. 3A and 3B, the apex 343 includes a grooveor channel 344 for receiving an adhesive prior to being coupled to afacing (not shown). In this embodiment, the width of the apex 343 isapproximately one fifth of the length of each linear leg supportstructure 321 and 342. Thus, this embodiment may be referred to as awide grooved apex flute profile 340. Other flute profiles arecontemplated but not discussed further for brevity.

FIG. 4 is an isometric cutaway view of a board product 400 having anembossed medium 130 with improved flute structure according to anembodiment of the subject matter disclosed herein. In this embodiment,the board product includes four layers: a first facing 110, a corrugatedmedium 120, an embossed medium 130, and a second facing 140. As isshown, the first facing 110 may form a top-side outer wall (although thetop/bottom direction reference to alignment of the board product 100 isarbitrary) that is coupled to one side of the corrugated medium 120. Thecoupling may be through an adhesive applied to the apex of each flute onthe top-side of the corrugated medium 120 such that the facing 110 isglued to the corrugated medium 120 where adhesive is applied. In otherembodiments, glue may be applied to the entirety of the facing 110 priorto being coupled to the corrugated medium 120.

Likewise, a second facing 140 may form a bottom-side outer wall (again,the top/bottom direction reference is arbitrary) that is coupled to oneside of the embossed medium 130. The coupling may be through an adhesiveapplied to the apex of each flute on the bottom-side of the embossedmedium 130 such that the facing 140 is glued to the embossed medium 140where adhesive is applied. In other embodiments, glue may be applied tothe entirety of the facing 140 prior to being coupled to the embossedmedium 130.

Further, the corrugated medium 120 and the embossed medium 130 may alsobe glued to each other using adhesive. Because the flutes of thecorrugated medium 120 are aligned in the cross direction and the flutesof the embossed medium 130 are aligned in the machine direction, thecontact points between these two mediums will be at the crossings of theapexes of the respective flutes. In this manner, the corrugated medium120 and the embossed medium 130 are affixed with respect to one anotherbecause of the adhesive holding one medium directly to the other.

When all four layers are assembled and affixed, the resultant boardproduct 400 is stronger than conventional board product because thelinearly embossed medium 130 includes a flute profile that exhibitssuperior strength because of the linear leg structures of each flute.Further, adhesive may be continuously and uniformly applied to each apexin a predictable and repeatable manner with greater precision asportions of the adhesive will not spill over to the legs as may be thecase with sinusoidal apexes having no flat receiving area. As shown inFIG. 4, the board product 400 includes a corrugated medium 120. In otherembodiments, the corrugated medium 120 may not be present such that thetop-side facing 110 is glued to each top-side apex of the embossedmedium and the bottom-side facing 140 is glued to each bottom side apexof the embossed medium 130. Additional aspects of the board product 400of FIG. 4 are discussed next with respect to the machine of FIG. 5.

FIG. 5 is a diagram of aspects of a machine 500 configured to producethe board product of FIG. 4 according to an embodiment of the subjectmatter disclosed herein. In this embodiment, the machine includes fourfeed rolls 510, 520, 530, and 540 of paper that are used to produce aboard product. These feed rolls include a first facing feed roll 510, acorrugated medium feed roll 520, an embossed medium feed roll 530, and asecond facing feed roll 540. Note that the paper that is wound on thecorrugated medium feed roll 520 is prior to corrugating and the paperthat is wound on the embossed medium feed roll 530 is prior toembossing. The weights and composition of the paper for each respectivefeed roll may be different and designed specifically for the respectivepurpose.

The paper from each roll may be unwound from each respective roll andfed toward a combiner 550 that is configured to combine the variouslayers of paper together to form a resultant board product. Prior toentering the combiner 550, at least some of the paper from the feedrolls may be passed through a stage for forming the paper into a medium.As used herein and in the industry, a medium may refer to a paperproduct that has been formed into paper having flutes. Thus, thecorrugated medium feed roll 520 may feed paper into first and secondcorrugating rolls 521 a and 521 b that are aligned with respect to eachother. As the paper exits the corrugating stage (e.g., corrugating rolls521 a and 521 b), it becomes the corrugated medium 120. The corrugatedmedium 120 is then fed into the combiner 550 to be combined with othermaterials. Similarly, the embossed medium feed roll 530 may feed paperinto first and second embossing rolls 531 a and 531 b that are alignedwith respect to each other. As the paper exits the embossing stage(e.g., embossing rolls 531 a and 531 b), it becomes the embossed medium130 as discussed above with respect to FIG. 1. The embossed medium 130is then fed into the combiner 550 to be combined with other materials.

Further, the embossed medium paper feed 530 may be first fed into aconditioner 560 that may condition the paper prior to embossing. Suchconditioning may include wetting the paper, heating the paper, coolingthe paper, applying chemicals to the paper and various other forms ofchanging the underlying condition of the paper to be better prepared forembossing. In this sense, one may think of the conditioning stage as“relaxing” underlying fibers of the paper such that the paper may be ina more compliant state to be manipulated easier so as to avoid tearingand ripping. Such condition may remove or modify inherent stiffness inthe paper and reduce the degree of possible fiber damage that will occurin the stretching process during embossing. In one embodiment, theconditioner may immerse (entirely or partially) the paper web in processin a liquid (e.g., water, recoverable solvent, and the like). The liquidmay be heated or not so as to achieve the desired paper condition ofcompliance/plasticity.

Once passed through the embossing rolls 531 a and 531 b, the embossedmedium 130 may be passed to an applicator 570 for applying adhesive tothe newly formed apexes. The applicator may include a device foridentifying the locations of each apex and then aligning a series ofadhesive dispensers with the identified apexes. In other embodiments,adhesive may be transferred to the flute tips with a glue roll or rollswhere the paper contacts a glue film and adheres to the flute tips. Inthis manner, adhesive may be applied with precision in a continuous anduniform manner. Then, the first facing 110, the corrugated medium 120,the embossed medium 130, and the second facing 140 are combined in thecombiner 550 using various techniques such as adhesion, curing, wetting,drying, heating, and chemical treatment. The resultant board product 400features at least one cross-corrugated medium 120 and at least onelinearly-embossed medium 130 wherein the linearly embossed mediumincludes a flute profile with improved structure.

While the subject matter discussed herein is susceptible to variousmodifications and alternative constructions, certain illustratedembodiments thereof are shown in the drawings and have been describedabove in detail. It should be understood, however, that there is nointention to limit the claims to the specific forms disclosed, but onthe contrary, the intention is to cover all modifications, alternativeconstructions, and equivalents falling within the spirit and scope ofthe claims.

What is claimed is:
 1. A board product, comprising: a first paper mediumhaving a machine direction aligned with a majority of underlying fibersand having a plurality of flutes aligned with the machine direction,wherein at least a set of the plurality of flutes each comprise a firstlinear leg support structure, a second linear leg support structure anda linear apex structure, wherein a first group of apex structures of theplurality of flutes comprise apex structures each having a respectiveelongated flat surface disposed in a first plane and a second group ofapex structures of the plurality of flutes comprise apex structures eachhaving a respective elongated flat surface disposed in a second planethat is different than the first plane; a second paper medium having aplurality of sinusoidal flutes, the second paper medium coupled directlyto at least some of the apex structures in the first group in the firstpaper medium; and a paper facing coupled directly to at least some ofthe apex structures in the second group in the first paper medium. 2.The board product of claim 1, further comprising a second facing affixedwith respect to the second paper medium.
 3. The board product of claim1, wherein the first linear leg structure and the second linear legstructure are affixed with respect to the paper facing at an anglebetween approximately 30 degrees and 60 degrees.
 4. The board product ofclaim 1, wherein each apex structure comprises a flat portion parallelto the paper facing.
 5. The board product of claim 1, wherein each apexstructure further comprises a flat portion having a groove configured tochannel an adhesive for coupling the at least some of the apexstructures to the paper facing.
 6. The board product of claim 1, furthercomprising a continuous adhesive line coupled between each apexstructure that is coupled to the paper facing.
 7. The board product ofclaim 1, wherein the first linear leg support structure comprises afirst linear dimension that is equivalent to a respective lineardimension of the second linear leg support structure and the apexstructure comprises a second linear dimension that is shorter than thefirst linear dimension.
 8. The board product of claim 7, wherein thefirst linear dimension is approximately ten times larger than the secondlinear dimension.
 9. The board product of claim 7, wherein the firstlinear dimension is approximately six times larger than the secondlinear dimension.
 10. The board product of claim 7, wherein the firstlinear dimension is substantially larger than the second lineardimension.
 11. The board product of claim 1, wherein the plurality offlutes comprise embossed flutes.
 12. The board product of claim 1,wherein the plurality of flutes comprise corrugated flutes.
 13. Theboard product of claim 1, wherein the plurality of flutes comprisescored flutes.
 14. The board product of claim 1, wherein the pluralityof flutes in the first medium comprise a first major flute direction andthe plurality of sinusoidal flutes in the second medium comprise asecond major flutes direction, wherein the first major flute directionis perpendicular to the second major flute direction when the firstmedium is coupled to the second medium.
 15. The board product of claim1, wherein the plurality of flutes in the first medium comprise a firstmajor flute direction and the plurality of sinusoidal flutes in thesecond medium comprise a second major flutes direction, wherein thefirst major flute direction is not congruent with the second major flutedirection when the first medium is coupled to the second medium.